The findings of two experiments conducted at the University of Pennsylvania explain:

Creative ideas are by definition novel, and novelty can trigger feelings of uncertainty that make most people uncomfortable.

People dismiss creative ideas in favour of ideas that are purely practical — tried and true.

Objective evidence shoring up the validity of a creative proposal does not motivate people to accept it.

Anti-creativity bias is so subtle that people are unaware of it, which can interfere with their ability to recognise a creative idea.

Obviously that doesn’t mean that every idea that makes you uncomfortable is simply a creative solution that you’re not comfortable with — bad ideas are still bad ideas — but you may want to think twice about why you’re not keen on a new idea.